Automotive air conditioner

ABSTRACT

An automotive air conditioner comprises an offset blower for blowing an air, an evaporator is centrally disposed within a dashboard and receives the air from below, and a heater approximately horizontally disposed above the evaporator. The evaporator inclines downward along the direction of the air flow. A plurality of condensed water guide plates are provided under the evaporator so as to allow a condensed water smoothly flow on the surface of each guide plate and is discharged from the evaporator through a condensed water drain pipe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.09/531,531 filed on Mar. 21, 2000; which is a continuation of U.S.patent application Ser. No. 09/460,795 filed Dec. 15, 1999; which is adivisional of U.S. patent application Ser. No. 09/038,902 filed Mar. 12,1995; which is a divisional of U.S. patent application Ser. No.08/731,792 filed Oct. 18, 1996, now U.S. Pat. No. 5,755,107; which is acontinuation-in-part of U.S. patent application Ser. No. 08/531,373filed Sep. 21, 1995, now abandoned. This application claims the benefitof JP 7-281479 filed Oct. 30, 1995; JP 7-270148 filed Oct. 18, 1995; JP7-235505 filed Sep. 13, 1995; JP 7-220903 filed Sep. 29, 1995; JP6-240362 filed Oct. 4, 1994; and JP 6-227592 filed Sep. 22, 1994. Thedisclosures of the above applications are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an automotive air conditioner, moreparticularly, to an arrangement for the automotive air conditioner unithaving heat exchangers which is disposed in approximately horizontaldirection and introduces the air generated by a blower from lower sidesof the heat exchangers.

2. Description of the Related Art

Generally, a conventional automotive air conditioner adopts so called“lateral layout”. This lateral layout is, as shown in FIG. 17, that afan unit 1, a cooler unit 2 a and a heater unit 2 b are arranged in linein the lateral (width) direction of the vehicle.

FIG. 18 shows the manner in which the lateral layout air conditioner ismounted within the vehicle. The vehicle has an instrumental panel ordashboard P. The fan unit 1, the cooler unit 2 a and the heater unit 2 bcollectively occupy a almost half space (which is formed in front of apassenger seat) in the dashboard P along the width direction of thevehicle.

Recently, a vehicle is provided with a great number of electroniccomponents such as computers, a compact disk player, a passenger air bagand other automotive accessories. This results in a decrease in thespace within the dashboard P and thus makes it difficult to mount such alateral layout air conditioner within the dashboard.

As shown in FIG. 19, there is shown another type of conventional airconditioner 2 arranged centrally within a vehicle and including, as aunit, a cooler or evaporator 21 and a heater core 22. The evaporator 21and the heater core 22 are arranged one after the other in thelongitudinal direction of the vehicle. A fan unit 1 is offset laterallyfrom the central portion of the vehicle.

This type of arrangement is so called center layout. The center layoutprovides a sufficient space within the dashboard to mount the evaporator21 and the heater core 22 since these components are both located at thecenter of the vehicle. However, since these heat exchangers (evaporator21 and heater core 22) are vertically arranged one above the other in alongitudinal direction of the vehicle, it is necessary to provide an airduct in front of the evaporator 21 so as to receive an air from the fanunit 1. By the same way, it is necessary to provide another air ductbehind the heater core 22 to allow an air flow from the heater core 22.

Consequently, those air ducts results in an increase in the overalllength of the air conditioner.

This increase makes it difficult to mount a blow mode selector behindthe heater core 22. To this end, the blow mode selector may be arrangedabove the heater core 22. However, this arrangement brings about anincrease in the height of the air conditioner.

Thus, such a center layout air conditioner is also difficult to mountwith a lot of electric components in the dashboard.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention toprovide a compact automotive air conditioner which enables mounting heatexchangers within a narrow vehicular space.

It is another object of the present invention to provide an automotiveair conditioner which promotes drainage of condensation from anevaporator.

To achieve the above objects, the present invention adopted thefollowing construction.

In one preferred mode of the present invention, an automotive airconditioner includes a blower, a cooling heat exchanger, a heating heatexchanger, and a blow mode selector.

The blower blows an air. The cooling heat exchanger is approximatelyhorizontally disposed between a dashboard within a passenger compartmentand an engine room and receives the air from its bottom side to anupward direction. The heating heat exchanger is approximatelyhorizontally disposed over the cooling heat exchanger and heats the air.The blow mode selector is disposed downstream of the heating heatexchanger and changes the direction of the air flown after the air isheated to a controlled temperature by the heating heat exchanger.

In another preferred mode of the present invention, the blower isdisposed between a dashboard within a passenger compartment and anengine room and offset in width direction of a vehicle from the centerof a width of vehicle.

Preferably, the cooling heat exchanger gradually inclines downward alongthe direction of the air flow which is generated by the blower.

Preferably, the cooling heat exchanger is inclined at an angle of 10 to30 degrees with respect to a horizontal plane.

Preferably, the air conditioner includes a case for directing the airfrom the blower to the cooling heat exchanger. The case has a condensedwater drain pipe for draining condensed water at a position below an airflow end of downwardly inclined the cooling heat exchanger.

Preferably, the automotive air conditioner includes guide elementslocated below the cooling heat exchanger. The guide elements aresubstantially in contact therewith.

Preferably, the case has a concave and convex surface having step shapeand extending in a width direction of the case to equal an air-blowspeed distribution measured by an air blow speed of the air introducedinto the cooling heat exchanger at a bottom surface of the cooling heatexchanger.

Preferably, the blower includes a scroll casing disposed approximatelyhorizontally, and the scroll casing has a winding end portion connectedto an air passage below the cooling heat exchanger. Further, an airguide plate is disposed on a downstream side of the cooling heatexchanger and extends from the scroll casing along the air flowdirection. In this way, the blow air by the blower from the scrollcasing is guided by the air guide plate, and the air blow speeddistribution in the longitudinal direction of the automobile can beuniformed. Accordingly, the uniform heat exchange can be performed ineach portion of the cooling heat exchanger, thus improving the heatexchanging efficiency and contributing to the uniformity of the air blowspeed distribution of the air flowing into the heating heat exchanger.

Preferably, an upper surface of the air guide plate contacts with abottom surface of the cooling heat exchanger so that the air guide platesupports the said cooling heat exchanger.

Preferably, the air guide plate partitions an air passage below thecooling heat exchanger into plural independent passages.

Preferably, the air guide plate includes a curved portion on an endthereof on a side of a centrifugal fan of the blower, and the curvedportion is bent smoothly along the air flow from the centrifugal fan.

Preferably, a unit case for containing the cooling heat exchanger isincluded, and the winding end portion is connected to a portioncorresponding to a lower side portion of the cooling heat exchanger, ofthe unit case. Further, a portion leading from the winding end portionto the unit case, of the scroll casing, extends approximately parallelto a width direction of the automobile, and the air guide plate isdisposed approximately parallel to a width direction of the automobile.

Preferably, a plurality of air distributing plates is disposed in aspace between the cooling heat exchanger and the heating heat exchanger,for uniforming air blow speed distribution of air in the heating heatexchanger in a width direction of the automobile.

Preferably, a unit case for containing the cooling heat exchanger isincluded, and the unit case includes a stepped concave and convexportion on a portion thereof corresponding to a lower portion of thecooling heat exchanger, for uniforming air blow speed distribution ofair flowing into the cooling heat exchanger in a width direction of theautomobile.

Preferably, an air conditioning unit case for containing the coolingheat exchanger and the heating heat exchanger and for forming an airpassage in which air generated by said blower passes is included, and adirection of the air passage is changed from a horizontal direction to avertical direction toward the downstream side. Further, the cooling heatexchanger includes a plurality of tubes in which heating medium forbeing heat exchanged with air which is generated by said blower passes,and a corrugated fin connected between each pair of the adjacent tubes,and the corrugated fin has a fin flat surface and is provided withlouvers for guiding air which is generated by said blower toward aninclination direction against the fin flat surface. The inclinationdirection being is so as to offset non-uniformity of air blow speeddistribution of air due to the changing direction of the air passage insaid air conditioning unit case.

Preferably, the inclination directions of the louvers of the corrugatedfin on an upstream side and on the downstream side of said fin flatsurface are reversed against each other, and the inclination directionof the louver of the corrugated fin at least on the downstream side isset so as to offset the non-uniformity of air blow speed distribution ofair.

Preferably, the cooling heat exchanger inclines downward with a minuteangle along the forwarding direction of the air flow which is generatedby said blower, and the plurality of tubes is disposed so as to extendbelow said cooling heat exchanger along the blowing direction of the airflow which is generated by said blower. Further, the cooling heatexchanger includes a tank portion for distributing and receiving theheating medium against the plurality of tubes on an upper end portionthereof in the inclination direction, and the inclination direction ofthe louver of the corrugated fin at least on the downstream side is setso as to direct the air flow by the blower toward the tank portion.

In another preferred mode of the present invention, blower is disposedso as to be offset from a central portion of a dashboard in a widthdirection of an automobile, a cooling heat exchanger is approximatelyhorizontally disposed within a dashboard, for receiving from its bottomside the air blown by the blower, cooling the air, and leading thecooled air toward an upward direction, and a heating heat exchanger isapproximately horizontally disposed over the cooling heat exchanger inthe central portion of a dashboard and for heating the air.

In further another preferred mode of the present invention, a blower isdisposed so as to be offset from a central portion of a dashboard in awidth direction of an automobile, a cooling heat exchanger isapproximately horizontally disposed within a dashboard, for receivingfrom its bottom side the air blown by the blower, cooling the air, andleading the cooled air toward an upward direction, and a blow modeselector is disposed over the cooling heat exchanger and for changingthe blowing direction of the air passing through the cooling heatexchanger.

In still another preferred mode of the present invention, a blower isdisposed so as to be offset from a central portion of a dashboard in awidth direction of an automobile, a heating heat exchanger isapproximately horizontally disposed, for receiving the air from itsbottom side the air blown by the blower, heating the air, and leadingthe heated air toward an upward direction, and a blow mode selectordisposed over the heating heat exchanger and for changing the blowingdirection of the air passing through the heating heat exchanger.

According to these preferred modes, both of the cooling heat exchangerand the heating heat exchanger are located substantially horizontallyand laminated vertically (one above the other), a vertical space for theheat exchanger portion can be greatly reduced. As a result, the verticaldimension of the air conditioning unit can be made sufficiently smallerthan that of the conventional center-layout unit.

Further, because the vertical dimension of the air conditioning unit canbe made sufficiently small as described above, even when the blow modeselector is disposed over the heating heat exchanger, the verticaldimension of the entire air conditioning apparatus can be suppressedfrom increasing.

Further, because it is unnecessary to provide blowing ducts on the frontand rear sides of the heat exchanger portion, the dimension in thelongitudinal direction of the vehicle can also be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to theaccompany drawings.

FIG. 1 is a plan view of an automotive air conditioner according to afirst embodiment of the present invention;

FIG. 2 is a front view of the air conditioner shown in FIG. 1;

FIG. 3 is a schematic view, in plane, showing the air conditioner of thefirst embodiment mounted within a vehicle;

FIG. 4 is a schematic view, in perspective, showing the air conditionerof the first embodiment mounted within the vehicle;

FIG. 5 is a disassembled view of the air conditioner of the firstembodiment;

FIG. 6 is side view showing the relationship between the air conditionerof the first embodiment and a partition located between an enginecompartment and a passenger compartment;

FIG. 7A is a graph showing the relationship between the angle θ ofinclination of an evaporator used in the first embodiment and theretained amount of condensed water which is left within the evaporator;

FIG. 7B is a perspective view showing the structure of the evaporator;

FIG. 8A is a sectional view showing the manner in which the condensatedrops from the evaporator in the event that the air conditioner isprovided with no guide plate;

FIG. 8B is a sectional view of the evaporator as viewed from right inFIG. 8A;

FIG. 9A is a sectional view of the evaporator associated with guideplates;

FIG. 9B is a sectional view of the evaporator as viewed from right inFIG. 9A;

FIG. 9C is a partial enlarged view of the guide plate of the evaporatorshown in FIG. 9B;

FIGS. 10A and 10B show the automotive air conditioner of the firstembodiment arranged for a right steering wheel vehicle;

FIGS. 11A and 11B show the automotive air conditioner of the firstembodiment arranged for a left steering wheel vehicle;

FIGS. 12A and 12B are sectional and plan views, respectively showing aguide plate used in a second embodiment of the present invention;

FIG. 13 is a graph showing the relationship between the inclined angle θof the evaporator and the amount of air to better drainage of thecondensed water with the guide plates used in the second embodiment ofthe present invention;

FIG. 14 illustrates guide plates used in a third embodiment of thepresent invention;

FIGS. 15A and 15B are sectional and plan views of the air conditionerhaving guide plates used in a fourth embodiment of the presentinvention, respectively;

FIG. 16 is a sectional side view of the second embodiment of the presentinvention;

FIG. 17 is a perspective view of a lateral layout type automotive airconditioner in the prior art;

FIG. 18 is a perspective view showing an automotive air conditionerarranged laterally within a vehicle in the prior art;

FIG. 19 is a perspective view of a center layout automotive. airconditioner arranged within a vehicle in the prior art;

FIG. 20 is a schematic view of the main part of the cooling unit to showthe air blow speed distribution;

FIG. 21 is a schematic view of the main part of the cooling unit in thesixth embodiment to show the air blow speed distribution;

FIG. 22 is a graph showing the relationship between air blow speed ratioand air guide plates;

FIG. 23A is a top view of the unit case (the evaporator and heater areeliminated) in the seventh embodiment;

FIG. 23B is a side sectional view of the unit case and the evaporator toshow a bottom shape of the unit case in the seventh embodiment;

FIG. 24A is a top view of the unit case (the evaporator and heater areeliminated) in modified example of the seventh embodiment;

FIG. 24B is a side sectional view of the unit case and the evaporator toshow a bottom shape of the unit case in modified example of the seventhembodiment;

FIG. 25 is a schematic sectional view of the unit case to show a slidedoor:

FIG. 26 is a plan view of an automotive air conditioner according to aneighth embodiment;

FIG. 27 is a perspective view of the automotive air conditioneraccording to the eighth embodiment;

FIG. 28 is a front view of an automotive air conditioner according tothe eighth embodiment;

FIG. 29 is a sectional view taken along the line C-C of FIG. 28;

FIG. 30 is a disassembled view of the air conditioner of the eighthembodiment;

FIG. 31 is a plane view showing an experimental device on both acomparison sample and the eighth embodiment;

FIG. 32 is a front view of the experimental device;

FIG. 33 is a sectional view showing a main portion of a ninthembodiment;

FIG. 34 is a sectional view showing a main portion of a tenthembodiment;

FIG. 35 is a perspective view showing a eleventh embodiment;

FIG. 36 is a perspective view showing a twelfth embodiment;

FIG. 37 is a schematic view, in plane, showing the air conditioner of athirteenth embodiment mounted within a vehicle;

FIG. 38 is a schematic view, in perspective, showing the air conditionerof the thirteenth embodiment mounted within the vehicle;

FIG. 39 is a front view of the thirteenth embodiment;

FIG. 40 is a sectional view showing a main portion of FIG. 39;

FIG. 41 is a disassembled view of the air conditioner of the thirteenthembodiment;

FIG. 42 is a perspective view showing an evaporator according to thethirteenth embodiment;

FIG. 43 is a partial perspective view showing a corrugated fin of thethirteenth embodiment;

FIG. 44A is a perspective view showing a main portion of a comparisonsample;

FIG. 44B is a front view showing a main portion of air blow speeddistribution in a comparison sample;

FIG. 45A is a perspective view showing a main portion of the thirteenthembodiment; and

FIG. 45B is a front view showing a main portion of air blow speeddistribution in the thirteenth embodiment;

FIG. 46 is a sectional view showing a main portion of a fourteenthembodiment; and

FIG. 47 is a sectional view showing a main portion of a fourteenthembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1

FIGS. 1 to 5 illustrate an automotive air conditioner according to afirst embodiment of the present invention. Referring specifically toFIGS. 3 and 4, a vehicle includes an engine compartment A and apassenger compartment B. These compartments A and B are divided by apartition C (generally referred to as a “fire wall ” and made from aniron plate). A dashboard P is arranged within the passenger compartmentB. The air conditioner comprises a fan unit 1 which is offset (to theleft wheel the vehicle has a right steering wheel) from the centralportion of the dashboard P in the width direction of the vehicle.

The fan unit 1 has an internal air/external air selector housing 11arranged at its top and adapted to allow for selective introduction ofinternal and external airs. The internal air/external air selectorhousing 11 includes an external air inlet 12 and internal air inlets 13.An internal air/external air selector door (not shown) is mounted withinthe internal air/external air selector housing 11 so as to selectivelyopen and close the external air inlet 12 and the internal air inlets 13.

As shown in FIG. 5, a blower 14 is mounted below the internalair/external air selector housing 11. The blower 14 includes acentrifugal multi-blade fan (scirocco fan) 15, a fan motor 16, and ascroll casing 17.

The fan 15 has a vertical rotary shaft. As the fan 15 rotates, an airflows from the internal air/external air selector housing 11 into thescroll casing 17 through a bellmouth-shaped inlet 18 (see FIG. 5) at thetop of the scroll casing 17. The air flows substantially horizontallythrough the scroll casing 17 and is directed toward an outlet (as isclear from FIG. 3, from the left side toward the right side of thepassenger compartment B).

An air conditioning unit 2 is arranged in the central portion of thedashboard P within the passenger compartment B and includes heatexchangers which will later be described. The air conditioning unit 2includes an evaporator (cooling heat exchanger) 21 disposed in anapproximately horizontal fashion. The air flows from the fan unit 1 andis introduced into the evaporator 21 from lower side.

A heater core (heating heat exchanger) 22 is disposed in anapproximately horizontal fashion and located downstream of (above) theevaporator 21 in the direction in which the air flows. The heater core22 utilizes an engine coolant (hot water) as a heat source. A blow modeselector 23 is located above (downstream of) the heater core 22.

In this embodiment, there is provided a hot water flow control valve 24(see FIG. 5) for controlling the flow of hot water to the heater core 22as a temperature control means. Under the control of the hot water flowcontrol valve 24, the heater core 22 adjusts the amount of heat appliedto the air and thus, the temperature of the air fed into the passengercompartment.

The blow mode selector 23 changes blow modes and includes a center faceair outlet 25 (see FIGS. 1 and 2) communicated with a center face(upper) air outlet (not shown) formed on the center of the dashboard, aside face air outlet 26 communicated with a side face air outlet (notshown) formed on right and left sides of the dashboard, a foot airoutlet 27 communicated with a foot (lower) air outlet (not shown) formedat the lower portion of the dashboard, and a defroster air outlet 28communicated with a defroster air outlet (not shown) formed on thedashboard at the front window side. An air is directed toward the headof a vehicle occupant through the center face air outlet and the sideface air outlet, toward the feet of the vehicle occupant through thefoot air outlet, and toward the windshield of the vehicle through thedefroster air outlet. The air outlet 25 to 28 are selectively opened andclosed by door means (in the form of a plate-like door, a rotary doorwith an arcuate outer surface, and a film-like door).

The blow mode selector 23 has a known structure and will not bedescribed herein. In this embodiment, the blow mode selector 23 iscylindrical in shape as shown in FIG. 6. A rotary door 23 a is rotatablydisposed within the blow mode selector 23 and has a cylindrical outerperipheral surface in which openings are defined to allow for thepassage of the air. The rotary door 23 a is rotated to open and closethe air outlets 25 to 28 to select a desired blow mode such as a faceblow mode, a bi-level blow mode, a foot blow mode, a defroster blowmode, foot/defroster mode.

As shown in FIG. 6, the evaporator 21 and the heater core 22 aredisposed adjacent to the partition C. Hot water pipes 22 a are connectedto the heater core 22 to allow hot water to flow into and out of theheater core 22. Similarly, refrigerant pipes 21 a are connected to theevaporator 21 to allow refrigerant to flow into and out of theevaporator 21. Both the hot water pipes 22 a and the refrigerant pipes21 a are located in the engine compartment A. The pipes 22 a and 21 a,when assembled, extend through the partition (fire wall) C into theengine compartment A.

During mounting of the automotive air conditioner, the hot water pipes22 a and the refrigerant pipes 21 a can be coupled within the enginecompartment A rather than the passenger compartment B. This arrangementfacilitates coupling of the pipes since it is not necessary to use sucha small space as the dashboard P.

Referring to FIG. 6, the partition C includes pipe holes (not shown)sealed by sealing members (grommet) G made of rubber or similar elasticmaterials. A temperature responsive expansion valve 21 b as a pressurereducing means is disposed between the evaporator 21 and the refrigerantpipes 21 a so as to reduce the pressure of and expand the refrigerant.

A condensed water is produced as a result of cooling. In order tofacilitate drainage of the condensed water, the evaporator 21 inclinesrelative to a horizontal plane as shown in FIG. 2, the evaporator 21 isso inclined downwardly that the end of the evaporator 21 that is furtherfrom the blower 14 is slightly inclined downwardly. The air from theblower 14 is directed to the bottom of the evaporator 21.

Referring to FIG. 7B, the evaporator 21 includes a plurality of thinplates made of aluminum or similar materials which has a high corrosionresistance and a high thermal conductivity. The thin plates arelaminated one above the other to form a multiplicity of tubes 21 f.Corrugated fins 21 g are disposed between adjacent tubes 21 f to providea core 21 h.

The evaporator 21 includes a tank 21 e connected to one end of the core21 h. The tank 21 e distributes the refrigerant to the tubes 21 f andcollects the refrigerant from the tubes 21 f. The refrigerant flows fromthe tank 21 e to the other end of the core 21 h and returns to the tank21 e (as shown by the arrow U in FIG. 7B).

The tank 21 e includes a refrigerant inlet 21 i for receiving arefrigerant in two phase, that is, gas and liquid, whose pressure isreduced by the expansion valve 21 b, and a refrigerant outlet 21 j fordischarging a refrigerant in gas phase which is evaporated in the core21 h.

The tubes 21 f of the evaporator 21 extend in the direction in which theair flows (from left to right in FIGS. 2 and 5). In this way, the airurges the condensed water toward the downwardly inclined end (right endin FIGS. 2 and 5) of the evaporator 21 along the tubes 21 f.

A lower case 29 a (see FIG. 5) is disposed below (upstream of) theevaporator 21 and made of resin. A condensed water drain pipe 21 c isintegrally connected to the bottom of the lower case 29 a andcorresponds in position to the downwardly inclined end of the evaporator21. The condensed water is discharged from the evaporator 21 throughthis drain pipe 21 c.

FIG. 5 is a disassembled view of the air conditioner. The motor 16 hasan output or rotary shaft 16 a connected to the fan 15. The fan 15 isdisposed within the scroll casing 17. The scroll casing 17 is integrallyformed in the lower case 29 a. The motor 16 has a flange 16 b fixedlysecured to the scroll casing 17.

The lower case 29 a has a mounting surface on which the evaporator 21 isplaced. The evaporator 21 is secured between the lower case 29 a and anintermediate case 29 b made of resin.

The intermediate case 29 b has an integral cover 17 a adapted to coverthe scroll casing 17 and including a bellmouth-shaped inlet 18. Theinternal air/external air selector housing 11 is integrally mounted tothe bellmouth-shaped inlet 18.

The intermediate case 29 b has a mounting surface on which the heatercore 22 together with the hot water flow control valve 24 is placed. Theheater core 22 is secured between the intermediate case 29 b and anupper case 29 c made of resin.

The blow mode selector 23, the center face air passage 25, the side faceair passage 26, the foot air passage 27, the defroster air passage 28and the rotary door 23 a are all formed in the upper case 29 c. Thecases 29 a to 29 c are detachably secured to the internal air/externalair selector housing 11 by known resilient metal clips, screws or othermeans.

With the air conditioner thus constructed, the evaporator 21 is arrangedin a substantially horizontal direction, and an air is blown from thelower end toward the upper end of the evaporator 21. Since the air flowsin a direction opposite to the condensed water dropping direction, thereis a need for any means for smoothly draining the condensed water fromthe evaporator 21.

To this end, this embodiment provides various means for facilitatingdrainage of the condensed water. Firstly, the evaporator 21 is slightlyinclined with respect to a horizontal plane. Referring specifically toFIGS. 2 and 5, an air is fed from the blower 14 to the bottom of theevaporator 21 and flows (to the right in FIGS. 2 and 5) from the rearend to the front end of the evaporator 21. The evaporator 21 is soinclined downwardly that the end of the evaporator 21 which is furtherfrom the blower 14 is slightly inclined downwardly, i.e., the evaporator21 gradually inclines downward along the direction of the air flow. Inorder to reduce the amount of condensed water left within the evaporator21, inventor studied and made a graph showing the relationship betweenretained amount of condensed water and arrangement angle θ formed fromthe horizontal plane and the lower end plane 21 n of the evaporator 21as shown in FIG. 7A. The evaporator 21 is preferably inclined at anangle θ of 10 to 30 degrees to reduce the retained volume of condensedwater as shown in FIG. 7A.

Secondly, the tubes 21 f of the evaporator 21 extend (to the right inFIG. 5) in a direction identical to the direction in which the airflows. By this arrangement, the condensed water is forced toward thedownwardly inclined end (right end in FIGS. 2 and 5) of the evaporator21 by the air while it flows on and along the tubes 21 f. The condensedwater is drained from the evaporator 21 through the condensed waterdrain pipe 21 c. The drain pipe 21 c is provided below the downwardlyinclined end of the evaporator 21 and integrally molded to the bottom ofthe lower case 29 a.

The inventor has carefully observed how the condensed water isdischarged from the air conditioner. As a result of this observation, ithas been found that as shown in FIGS. 8A and 8B, the condensed water isdirected toward the downwardly inclined end of the evaporator 21 undergravity and air pressure to form small droplets W. When those dropletscoalesce and grow to form a certain size of droplet, then it drops fromthe evaporator 21. This occurs in an intermittent manner.

With this in mind, the inventor reached an idea to continuously move thecondensed water to the drain pipe 21 c of the case 29 a before thedroplets W reaches a certain size to be dropped.

To this end, a plurality of vertical guide plates 21 k are located belowthe downwardly inclined end of the evaporator 21 to which the droplets Ware directed as shown in FIGS. 9A, 9B and 9C. The guide plates 21 k aresubstantially in contact with (or may be separated a very small distanceaway from) the tubes 21 f. In this embodiment, the guide plates 21 k areintegrally formed in the lower case 29 a. As shown in FIG. 9B, the guideplates 21 k are arranged at predetermined intervals along the width ofthe downwardly inclined end of the evaporator 21.

The lower case 29 a has a side wall 29 a′. The guide plates 21 k arespaced as at 21 m from the side wall 29′ as shown in FIG. 9A. The drainpipe 21 c is located below this space 21 m.

Operation of the air conditioner thus constructed will now be described.Referring to FIG. 5, an air flows from the internal air/external airselector housing 11 into the scroll casing 17. The, the fan 15 causesthe air to flow horizontally through the scroll casing 17. The air isdried and cooled until it reaches the lower part of the evaporator 21.Thereafter, the air flows upward and enters the heater core 22. The airis heated within the heater core 22.

In this embodiment, the hot water flow control valve 24 is employed as atemperature control means to control the flow of hot water fed to theheater core 22. The hot water flow control valve 24 is of the type, aso-called adjustable flow reheat type, which adjusts the flow of the hotwater to provide an air of a desired temperature. The air is distributedto a desired air outlet through the rotary door 23 a of the blow modeselector 23 after it is reheated to a desired temperature within theheater core 22.

This embodiment offers the following advantages.

(1) The evaporator 21 and the heater core 22 extend in a substantiallyhorizontal direction and are laminated one above the other. An air isintroduced into the evaporator 21 from below and then moved upwards.This arrangement eliminates the need for longitudinally extending airducts and thus, enables a substantial reduction in the size of the airconditioning unit in the longitudinal direction of the vehicle.

Also, the vertical space occupied by the heat exchangers is reduced toallow for mounting of the air conditioning unit in the vehicle easily.

(2) The heat exchanger pipes 21 a and 22 a extend into the enginecompartment A. This arrangement eliminates the need for auxiliary pipeswithin the passenger compartment B, substantially reduces the productioncost, and facilitates coupling of the pipes.

(3) As shown in FIG. 5, most of the air conditioner components in thepresent invention are arranged in a vertical fashion. The components areassembled from the bottom to the top. This manner of assembly enables areduction in the number of production steps.

(4) The evaporator 21 is designed to receive an air from below and isinclined downwardly toward the direction along which the air flows. Thetubes 21 f of the evaporator 21 are oriented in a direction identical tothe direction in which the air flows. The air causes a condensed waterto flow on the surfaces of the tubes. Thus. the condensed water issmoothly directed toward the downwardly inclined end (right end in FIG.2) of the evaporator 21.

Moreover, the vertical guide plates 21 k are located below andsubstantially in contact with the downwardly inclined end of theevaporator 21. As shown in FIG. 9C, a condenses water is directed to thedownwardly inclined end of the evaporator 21 and then extended betweenthe front end of the evaporator 21 and each guide plate 21 k. Thecondensed water is continuously moved down along the surface of eachguide plate 21 k.

Even if the evaporator 21 is arranged in an approximately horizontaldirection and designed to receive the air from below, the condensedwater is smoothly moved downward without growing to a large droplet. Thespace 21 m is left between the guide plates 21 k and the side wall 29 a,of the lower case 29 a. The drain pipe 21 c is located below this space21 m to smoothly discharge the condensed water after it is moved downalong the guide plates 21 k. Experiments have shown that the condensedwater forms a bridge or is extended between the guide plates 21 k andthe evaporator 21 and is continuously moved down along the surface ofeach guide plate 21 k.

(5) As the condensed water is moved upstream of or below the evaporator21, it contacts a relatively high temperature air which has not yet beencooled. Since the temperature of the condensed water increases, there isno substantial decrease in the temperature of the outer surface of thelower case 29 a. This substantially reduces or avoids the occurrence ofdewdrops, so that an insulator (thermal insulator) to be installedwithin the case is eliminated. This enables a further reduction in theproduction cost.

However, the amount of the condensed water left within the evaporator 21varies depending on the angle θ of inclination of the evaporator 21 asshown in FIG. 7A. To reduce the amount of condensed water left withinthe evaporator 21, it is imperative that the evaporator 21 is inclinedat an angle θ of 10 to 30 degrees.

(6) An engine and an air compressor, whether a steering wheel is mountedat the right side or left side of the vehicle, are normally mounted in afixed position within the engine compartment A. It is desirable to formpipe holes in the partition C in the same position regardless of whetherthe steering wheel is mounted at the right side or the left side of thevehicle.

To meet this need, in the embodiment shown in FIGS. 10A, 10B, 11A and11B, the offset position of the blower 14 and the position of therefrigerant pipe 21 a of the evaporator 21 (the position of the tank 21e of the evaporator 21) are laterally reversed. Similarly, the positionof the hot water pipe 22 a of the hot water flow control valve 24 in theheater core 22 is laterally reversed.

Embodiment 2

Referring to FIGS. 12A and 12B, the guide plate 21 k has a cross shapeto improve drainage of the condensed water. Specifically, thecross-shaped guide plate 21 k has a flange 210 k to stop the flow of theair and prevent upward flow of the air behind the flange 210 k.

By this arrangement, the condensed water can more easily drop behind theflange 210 k for better drainage. As an alternative, the guide plate 21k may have a T-shape to facilitate drainage of the condensed water.

FIG. 13 shows effects of the second embodiment. The vertical axisindicates the flow of air when 12 volts are applied to the fan motor 16(see FIG. 5). The horizontal axis indicates the angle of inclination ofthe evaporator 21 with respect to a horizontal plane.

Referring to FIG. 13, the solid line shows the case in which thecross-shaped guide plates 21 k of the second embodiment are provided.The broken line shows the case in which no cross-shaped guide plate 21 kis provided.

As is shown, the cross-shaped guide plates 21 k promote drainage of thecondensate to reduce the amount of the condensed water left within theevaporator 21 and thus, the resistance to flow is also reduced. Thisresults in an increase in the flow of air and thus, in betterperformance of the air conditioner.

Referring to FIG. 11, through experiments, it has been found that theevaporator 21 is preferably inclined at an angle θ of 10 to 30 degrees.

Embodiment 3

Referring to FIG. 14, the guide plates 21 k are flat and inclined withrespect to the direction of flow of the air. The guide plate 21 k has arear surface 211 k. The upward flow of the air is retarded behind therear surface 211 k so as to allow the condensed water to easily dropbehind the rear surface of each guide plate 21 k.

Embodiment 4

Referring to FIG. 15A, the lower case 29 a has a wavy portion 21 k′ at aposition below the downwardly inclined end of the evaporator 21. Thewavy portion 21 k′ corresponds to the guide plates 21 k and functions todirect the condensed water out of the evaporator 21.

In the foregoing embodiments, the guide plates 21 k and the wavy portion21K′ are integral with the lower case 29 a, made of resin, tosubstantially reduce the production cost. However, these members 21 kand 21 k′ need not be integral with the lower case 29 and may bediscrete members with the same function. In such a case, these members21 k and 21 k′ may be attached to the lower case 29 or the evaporator 21by any suitable means.

Embodiment 5

Referring to FIG. 16, an air mixing door 30 as a temperature controlmeans may be employed in lieu of the adjustable flow reheat type usingthe hot water flow control valve 24. The blow mode selector 23 includesplate-like doors 23 b and 23 c in lieu of the rotary door 23 a. Thedoors 23 b and 23 c serve as a means for allowing a selection of one ofthe air passages. As in the first embodiment, the horizontal evaporator21 is designed to receive an air from below and direct the air towardthe horizontal heater core 22. This arrangement offers the same effectas in the previous embodiment. A further advantage of this air mixturemethod is that the temperature of the air can be controlled in a widerange, from low to high temperatures.

On the other hand, the use of the air mixing door 30 slightly increasesthe height of the unit as compared to the previous embodiment.

In the forgoing embodiments, the evaporator 21 is not limited to thelaminated type evaporator. For example, serpentine type evaporatorformed from flat tubes having a serpentine shape and corrugated fins isalso available to be used.

Embodiment 6

The sixth embodiment is explained with FIGS. 20 to 23. In theembodiments described in the above, since the evaporator 21 is disposedto gradually incline downward along the direction of the air flow whichflows into the evaporator 21 from the lower surface of the evaporator21, the cooled air through the evaporator 21 flows obliquely into theheater 22 as shown as an arrow D in FIG. 20. Consequently, adistribution of the air blow speed (shown as air blow speed distributionE in FIG. 20) in the right and left direction in Figure, (i.e., alongthe width direction of the vehicle) in the heater 22 is dispersed. Theair flow speed passing through the heater 22 increases as the air flowpasses the right side of the heater 22 in the figure as shown as thedistribution E. Further, the dispersion of the air blow speeddistribution causes a dispersion of heat exchange amount in the rightand left side of the heater 22, so that the air blow temperature alsodisperses. Consequently, an air conditioning feeling for the automotiveair conditioner differs at right and left side of the compartmentbecause of the dispersion of the air blow speed distribution and the airblow temperature, thereby the occupants feel bad air conditioningfeeling.

In the sixth embodiment, a plurality of air guide plates 31 is sodisposed in the air flow passage between the evaporator 21 and theheater 22 as shown in FIG. 21 that the air blow speed distribution inthe heater 22 is uniformed. The air guide plate 31 is disposedperpendicularly to an air introduction surface of the heater 22. Aplurality of the air guide plates 31 are arranged at the same intervals(in the figure three guide plates are arranged). Since the air guideplates 31 are formed integrally with a resin case (specifically, theintermediate case 29 b) of the air conditioner, the air guide plates canbe simply produced in low production cost. The air guide plates 31forcedly guide the air from the evaporator 21 to the heater 22 to flowinto the heater 22 perpendicularly to the air introduction surface ofthe heater 22. Thereby, the dispersion of the air blow speeddistribution in the heater 22 is so improved that the air blow speeddistribution can be uniformed as shown as F in FIG. 21.

FIG. 22 shows concrete numerical performance based on the inventor'sexperiments. The experiment was performed with three air guide plates 31and air passages divided into quarters with the guide plates 31 at theside of the air introduction surface of the heater 22. The air blowspeed ratio is a ratio between the maximum air blow speed (Vmax) and theminimum air blow speed (Vmin). When the width of the heater in right andleft direction in the figure is 220 mm and the air blow speed is 480m³/h, the air blow speed ratio with no guide plates 31 is 0.60 and thatwith guide plates 31 is improved to 0.85 as shown in FIG. 22.

Embodiment 7

In the seventh embodiment, the air blow speed distribution of the airflowing into the evaporator 21 is uniformed and a drainage of thecondensed water generated on the evaporator 21 is secured compatibly asshown in FIGS. 23A and 23B. Since the air from the blower 14 of theblower unit 1 flows upward by perpendicularly converting under theevaporator 21, the air blow speed at the forward side (the right side inFIG. 23B) of the air flow direction becomes high.

In this embodiment, a concave and convex surface 32 having step shape isintegrally formed to the resin case (specifically, the intermediate case29 a) under the evaporator 21, thereby uniformity of the air blow speeddistribution of the evaporator 21 is achieved. The concave and convexsurface 32 having the step shape is extended perpendicularly to the airflow (defined as G as shown in FIG. 23B) from the blower 14.

The concave and convex surface 32 has two ridges at each top of the stepshape as shown in FIG. 23B and also has a steep slope 32 a at theupstream side and an easy slope 32 b at the downstream side. Accordingto the inventor's experiments, a preferable difference in level betweenthe ridge and bottom of the concave and convex surface 32 is in therange of about 15 to 20 mm to uniform the air blow speed distribution.

As shown in FIGS. 23A and 23B, when the concave and convex surface 32 isformed in entire length of the depth direction (the longitudinaldirection of the vehicle) of the lower case 29 a, the condensed water His collected at the bottom of the concave and convex surface 32. Whilethe blower 14 operates, the drainage from the condensed water dischargepipe 21 c is performed in some extent by pushing out the condensed waterfrom the bottom of the concave and convex surface 32 with the air flowproduced by the blower 14. However, when the blower 14 stops, thecondensed water retained on the evaporator 21 drops and pools at thebottom of the concave and convex surface 32. This may cause a nastysmell.

Therefore, to achieve both the uniformity of the air blow speeddistribution of the air introduced into the evaporator 21 and thedrainage of the condensed water generated in the evaporator, drainchannels 33 which is lower than the bottom of the concave and convexsurface 32 are formed at three locations around the concave and convexsurface 32 and are communicated with the condensed water discharge pipe21 c. Since the lower case 29 a is also inclined along the downwardinclination of the evaporator 21 which is along the direction of the airflow, the drain channel 33 is also inclined downward along the directionof the air flow. The discharge pipe 21 c is disposed at the lowest levelof the drain channel 33. By adopting the above construction, thecondensed water H dropped from the evaporator 21 is led to the drainchannel 33 from the bottom of the concave and convex surface 32 and issmoothly discharged from the discharge pipe 21 c.

In FIG. 24A, the drain channels 33 are formed at three portions aroundthe concave and convex surface 32, however, it is possible to parallelyform an additional drain channel 33 at the center of the two paralleldrain channels 33. Further, it is possible to eliminate one of the twoparallel drain channels 33. Still further, the drain channel 33 isdesigned to be lower level than the bottom of the concave and convexsurface 32 in the above embodiment, however, the inventor experimentedand confirmed that the condensed water can be discharged even if thedrain channel 33 is the same level as the bottom of the concave andconvex surface 32.

In the present invention described above, the air mixing door 30 is usedas temperature adjusting means. In this case, the large verticaldimension of the cooling unit is a demerit. As a modified embodiment, aslide door 100 which is a flat plate and slides right and left directionin FIG. 25 is proposed in FIG. 25. This slide door 100 can reduce thevertical dimension of the cooling unit. The way of driving the slidedoor 100 is explained hereinafter. A driving gear 102 engages with aintermediate gear 101. The intermediate gear is connected with the slidedoor 100. When the driving gear 102 is driven to rotate, theintermediate gear 101 is rotated and the slide door 100 is moved rightand left direction in FIG. 25.

Embodiment 8

An eighth embodiment of the present invention will be described withreference to FIGS. 26-30.

Referring to FIG. 26, an engine compartment A and a passengercompartment B is partitioned by a partition C (generally referred as a“fire wall” and made from an iron plate). A fan unit 1 of an airconditioner is so located as to be offset from the central portion ofthe dashboard P in the width direction of the vehicle (e.g., offset tothe left wheel the vehicle has a right steering wheel).

As shown in FIG. 27, the fan unit 1 has at its upper portion an internalair/external air selector housing 11 for selectively introducing airinside the passenger compartment and air outside the passengercompartment. The internal air/external air selector housing 11 is formedwith an external air inlet 12 for introducing the external air and aninternal air inlet 13 for introducing the internal air. Inside theinternal air/external air selector housing 11, there is provided aninternal/external air selector door (not shown) for opening or closingthe external air inlet 12 and the internal air inlet 13.

A blower 14 is provided below the internal air/external air selectorhousing 11. The blower 14 is composed of a centrifugal multiblade fan(scirocco fan) 15, a fan driving motor 16, and a scroll casing 17.

A rotary shaft of the fan 15 is so arranged as to direct in asubstantially vertical direction. The air sucked by rotation of the fan15 from the internal air/external air selector housing 11 through abellmouth shaped air inlet 18 (see FIG. 30) formed at an upper portionof the scroll casing 17 is directed toward an outlet of the scrollcasing 17 in a substantially horizontal direction (from the left to theright in the passenger compartment B as understood from FIG. 26).

As shown in FIG. 26, an air conditioner unit 2 incorporating an airconditioning heat exchanger which will be described later is located atthe central portion of the dashboard P in the passenger compartment B inthe width direction of the vehicle. In the air conditioning unit 2, anevaporator (cooling heat exchanger) 21 of a refrigeration cycle islocated substantially horizontally, and the air directed from the fanunit 1 enters the evaporator 21 from its lower side.

As shown in FIGS. 27 and 28, a heater core (heating heat exchanger) 22is located substantially horizontally on the downstream side of theevaporator 21 with respect to the airflow direction (on the upper sidein the passenger compartment). The heat core 22 utilizes an enginecooling water (hot water) as a heat source. A blow mode selector 23 (seeFIG. 28) is located on the upper side of the heat core 22 in thepassenger compartment (on the downstream side of the heater core 22).

In this embodiment, there is provided a hot water flow control valve 24(see FIG. 40) for controlling a hot water flow to the heater core 22 astemperature control means for controlling temperature of conditionedair, so that the hot water flow to the heater core 22 is controlled bythe hot water flow control valve 24 to thereby adjust an amount of heatof air by the heater core 22 and control a temperature of air to besupplied into the passenger compartment.

The blow mode selector 23 is provided to select a blow mode of air to besupplied into the passenger compartment. The selecting member 23includes a center face air passage 25 communicated with a center face(upper) air outlet (not shown) for discharging air toward the head of apassenger in the passenger compartment, two side face air passages 26communicated with two side face air outlets (not shown) for dischargingair toward the head of the passenger from the right and left sidesthereof, two foot air passages 27 communicated with two foot (lower) airoutlets (not shown) for discharging air toward the feet of thepassenger, and a defroster air passage 28 communicated with a defrosterair outlet (not shown) for discharging air toward a windshield. The blowmode selector 23 further includes door means (a plate door, a rotarydoor having a cylindrical outer peripheral surface, or a film door) forselectively opening or closing these air passages 25, 26, 27, and 28.

The blow mode selector 23 may have a known structure, and the detaileddescription thereof will be omitted herein. However, in brief, the blowmode selector 23 has a cylindrical shape extending laterally (in theright-left direction) as shown in FIG. 28. A rotary door (not shown) isrotatably provided in the blow mode selector 23 and has a cylindricalouter peripheral surface in which openings are defined to allow for thepassage of the air. By selecting a rotational position of the rotarydoor, the air passages 25, 26, 27, and 28 are selectively opened orclosed to select a desired one of a plurality of blow modes including aface blow mode, a bi-level blow mode, a foot blow mode, a defroster blowmode, and a combined foot and defroster blow mode. In FIG. 27, the blowmode selector 23 is not shown for simplicity of illustration.

The evaporator 21 is slightly inclined with respect to a horizontalplane, so as to improve the drainage of condensed water generated by thecooling operation. That is, as shown in FIGS. 27 and 28, the evaporator21 is inclined downward at its one end (in the right direction in FIG.28) corresponding to the forward end of the flow of air directed to thelower side of the evaporator 21 by the blower 14.

An angle θ of inclination of the evaporator 21 is set to preferably 10to 30 degrees to reduce an amount of water retained in the evaporator 21itself.

The evaporator 21 is of a known laminated type such that its coreportion is formed by laminating a plurality of metal thin plates ofaluminum or the like which are superior in heat conductivity andcorrosion resistance in a direction perpendicular to the sheet plane ofFIG. 30 to construct a plurality of tubes 21 a, and by interposing acorrugated fin (not shown) between each adjacent pair of the pluralityof tubes 21 a. As shown in FIG. 30, a tank portion 21 b for distributinga refrigerant to the tubes 21 a and collecting the refrigerant from thetubes 21 a is provided at one end of the evaporator 21. Further, athermal type expansion valve 21 c is provided adjacent to the tankportion 21 b and reduces the pressure of the refrigerant flowing intothe evaporator 21 to expand the refrigerant.

The tubes 21 a of the evaporator 21 extend in the same direction as theflowing direction of the air from the blower 14 (from the left to theright in FIG. 28). Accordingly, the condensed water is forced by the airflow to smoothly flow on the surfaces of the tubes 21 a to the lower endof the inclined evaporator 21 (the right end in FIG. 28).

The condensed water generated in the evaporator 21 is discharged from acondensed water drain pipe 21 d provided below the lower end of theinclined evaporator 21 on the lower side thereof (on the upstream sideof the evaporator 21). The pipe 21 d is integrally formed with a resinlower case 29 a (see FIG. 30) of resin at its lowermost portion.

An air guide plate 30 is located below the evaporator 21, that is, onthe upstream side of the evaporator 21, in such a manner as to extendalong the air flow from the blower 14. In this embodiment, the air guideplate 30 is integrally formed with the resin lower case 29 a. As will bedescribed later, the air guide plate 30 serves to uniform an air blowspeed distribution of air passing through the evaporator 21 in thelongitudinal direction of the vehicle.

As shown in FIG. 28, an upper surface 30 a of the air guide plate 30 isinclined along the inclined lower surface of the evaporator 21. Theinclined upper surface 30 a of the air guide plate 30 is in contact withthe inclined lower surface of the evaporator 21 to thereby support theevaporator 21. The air passage formed below the evaporator 21 ispartitioned into two independent passages by the air guide plate 30.

FIG. 30 shows a structure where the apparatus is assembled in thisembodiment. The fan 15 of the blower 14 is integrally connected to arotary shaft 16 a of the motor 16, and then inserted into the scrollcasing 17 formed integrally with the resin lower case 29 a. In thiscondition, the motor 16 is fixedly mounted at its flange portion 16 b tothe scroll casing 17.

The evaporator 21 is placed on an mounting surface of the lower case 29a, and a resin intermediate case 29 b is put on the lower case 29 a soas to sandwich the evaporator 21. Thus, the evaporator 21 is fixedbetween the lower case 29 a and the intermediate case 29 b.

An upper cover portion 17 a of the scroll casing 17 is formed integrallywith the intermediate case 29 b. The upper cover portion 17 a has thebellmouth shaped air inlet 18 described above. The internal air/externalair selector housing 11 is located on the bellmouth shaped air inlet 18and integrally mounted thereto.

The heater core 22 and the hot water flow control valve 24 are placed ona mounting surface of the intermediate case 29 b, and a resin upper case29 c is put on the intermediate case 29 b so as to sandwich the heatercore 22 and the hot water flow control valve 24. Thus, the heater core22 and the hot water flow control valve 24 are fixed between theintermediate case 29 b and the upper case 29 c.

The upper case 29 c is provided with the blow mode selector 23, centerface air passage 25, side face air passages 26, foot air passages 27,and defroster air passage 28. Further, the rotary door (not shown) isbuilt in the upper case 29 c. The cases 29 a, 29 b, and 29 c and theinternal air/external air selector housing 11 are detachably connectedby using metal clips having elasticity or screws.

An operation of the eighth embodiment having the above structure willnow be described.

Referring to FIGS. 27 and 28, the air flowing into the internalair/external air selector housing 11 is directed into the scroll casing17 by the fan 15, and flows substantially horizontally in the scrollcasing 17 to the lower side of the evaporator 21. Then, the air isdehumidified and cooled in the evaporator 21, and flows upward to enterthe heater core 22, in which the air is heated.

In this embodiment, the hot water flow control valve 24 for controllingthe amount of hot water to be supplied to the heater core 22 is used asconditioned air temperature control means. That is, a so-called flowcontrol reheat system is adopted to obtain a desired blow airtemperature by controlling the amount of hot water in the hot water flowcontrol valve 24. The conditioned air reheated to a desired temperaturein the heater core 22 is distributed to a predetermined air passageselected by the rotary door of the blow mode selector 23 in the uppercase 29 c.

With the above configuration of the embodiment, the following effectscan be obtained.

(1) Because the evaporator 21 and the heater core 22 are locatedsubstantially horizontally and laminated vertically (one above theother), a vertical space for the heat exchanger can be greatly reduced.As a result, the vertical dimension of the air conditioning unit can bemade sufficiently smaller than that of the conventional center-layoutunit. Further, since it is unnecessary to provide blowing ducts on thefront and rear sides of the heat exchanger, the dimension in thelongitudinal direction of the vehicle can also be reduced. Thus, the airconditioning unit can be made greatly compact, and it can be easilyinstalled in the passenger compartment.

(2) Since most of the components of the air conditioning unit have suchshapes as to be assembled vertically as shown in FIG. 30, the airconditioning unit can be easily assembled by one-directional assemblingsuch that the components are vertically laminated, so that the number ofthe assembling steps in the mass-production can be reduced.

(3) Since the evaporator 21 is inclined downward at its one endcorresponding to the forward end of the flow of air directed from theblower 14, and the tubes 21 a of the evaporator 21 extend along the airflow (in the left-right direction in FIGS. 27 and 28), the condensedwater in the evaporator 21 is forced by the air flow to smoothly flow onthe surfaces of the tubes 21 a, is collected at the end of the inclinedevaporator 21 (the right end in FIGS. 27 and 28), and drops.

Then, the condensed water is discharged from the drain pipe 21 d locatedbelow the lower end of the inclined evaporator 21. Thus, the condensedwater can be smoothly discharged from the evaporator 21.

(4) Because the condensed water in the evaporator 21 drops to theupstream side thereof, the condensed water is warmed by the hot airbefore cooled. Accordingly, the temperature of the outer surface of thelower case 29 a is not so decreased, and as a result, droplet on thelower case 29 a can be greatly reduced or eliminated. In this way, it isunnecessary to provide a heat insulator usually mounted inside a case.

(5) By installing the air guide plate 30, the air blow speeddistribution of air passing through the evaporator 21 in thelongitudinal direction of the vehicle can be uniformed. An effect of theair guide plate 30, which is a main feature of the present invention,will now be described.

FIG. 29 is a cross section taken along the line C-C in FIG. 28.Referring to FIG. 29, a winding end portion 17 b of the scroll casing 17of the blower 14 is connected to a portion of the lower case 29 a belowthe evaporator 21, and a connecting portion between the winding endportion 17 b and the lower case 29 a extends substantially parallel tothe width direction of the vehicle (see FIG. 26).

As shown in FIG. 26, the air guide plate 30 is so arranged as to extendsubstantially parallel to the width direction of the vehicle. A flowingdirection D of air directed from the winding end portion 17 b of thescroll casing 17 is coincident with a direction of a tangent to thewinding end portion 17 b, and the flowing direction D is headed for aregion R on the side of the passenger compartment in the lower case 29a.

If the air guide plate 30 is not provided, the air blow speeddistribution of air passing through the evaporator 21 in thelongitudinal direction of the vehicle may become non-uniform such thatthe air blow speed in the region R on the side of passenger compartmentis higher than that in the region E on the side of the enginecompartment. Such a non-uniform air blow speed distribution causesproblems in deterioration of the heat exchanging efficiency in theevaporator 21.

The inventors measured the above air blow speed by using an experimentaldevice shown in FIGS. 31 and 32 on both a comparison sample withouthaving the air guide plate 30 and this embodiment having the air guideplate 30.

The experimental device shown in FIGS. 31 and 32 is constructed byremoving the heater core 22 and the like on the downstream side of theevaporator 21 and placing an air blow speed measuring duct F dividedinto eight portions. In FIG. 31, E1 to E4 denote four openings on theside of engine compartment, of the air blow speed measuring duct F, andR1 to R4 denote four opening portions on the side of the passengercompartment.

TABLES 1A and 1B show the results of measurement of the air blow speedby using the above experimental device, in which TABLE 1 shows theresult of the comparison sample without having the air guide plate 30,and TABLE 2 shows the result of this embodiment having the air guideplate 30. In TABLE 1A and 1B, portions 1-4 respectively correspond tothe numerals 1-4 given to each opening portion. The blower 14 isoperated by applying voltage of 12 V to the driving motor 16. TABLE 1AIR BLOW SPEED DISTRIBUTION WITHOUT AIR GUIDE PLATE PORTION 1 3 3 4ENGINE COMP. SIDE (E) 4.9 7.5 8.6 9.1 PASSENGER COMP. SIDE (R) 5.9 7.98.9 9.5 ENGINE SIDE AVERAGE SPEED 7.5 PASSENGER COMP. SIDE AVERAGE SPEED8.1ENGINE SIDE/PASSENGER COMPARTMENT SIDE = 0.92

TABLE 2 AIR BLOW SPEED DISTRIBUTION WITH AIR GUIDE PLATE (ONE PLATE)PORTION 1 3 3 4 ENGINE COMP. SIDE (E) 5.3 7.8 8.8 9.6 PASSENGER COMP.SIDE (R) 5.5 7.6 8.3 9.3 ENGINE SIDE AVERAGE SPEED 7.9 PASSENGER COMP.SIDE AVERAGE SPEED 7.7ENGINE SIDE/PASSENGER COMPARTMENT SIDE = 0.97

In the comparison sample without having the air guide plate 30, the airvelocities at opening portions R1 to R4 on the side of the enginecompartment are higher than those at opening portions E1 to E4 on theside of the passenger compartment, for the aforementioned reason. Asshown in TABLE 1A, an average air blow speed on the side of the enginecompartment is 7.5 m/s, and an average air blow speed on side of thepassenger compartment is 8.1 m/s. Accordingly, the ratio between theaverage air blow speed on the engine compartment side and the averageair blow speed on the passenger compartment side becomes 7.5/8.1=0.92.

To the contrary, according to this embodiment having the air guide plate30, the flowing direction D of air directed from the winding end portion17 b of the scroll casing 17 toward the region R on the side of thepassenger compartment can be changed toward the region R on the side ofthe engine compartment. Accordingly, as shown in TABLE 1B, the averageair blow speed on the side of the engine compartment and the average airblow speed on the side of the passenger compartment can approach eachother so that the average air blow speed on the side of the enginecompartment is increased up to 7.9 m/s and the average air blow speed onthe side of the passenger compartment is decreased down to 7.7 m/s.Accordingly, the ratio between the average air blow speed on the side ofthe passenger compartment and the average air blow speed on the side ofthe engine compartment becomes 7.7/7.9=0.97. Thus, the differencebetween the two average air velocities can be reduced to a minute valuearound an error.

The flowing direction D of air from the winding end portion 17 b of thescroll casing 17 cannot be changed toward the region E on the side ofthe engine compartment, because it may cause problems such as adeterioration of the performance of the blower and an increase of theinstallation space in the passenger compartment.

Embodiment 9

FIG. 33 shows a ninth embodiment of the present invention. In thisembodiment, two air guide plates 30 are provided to partition the airpassage below the evaporator 21 into three independent regions(passages) E, M, and R. The other configuration is the same as that ofthe eighth embodiment.

Embodiment 10

FIG. 34 shows a tenth embodiment of the present invention. In thisembodiment, a gently curved portion 30 a along the air flow from thecentrifugal fan 15 is formed at one end of the air guide plate 30 on theside of the centrifugal fan 15. By forming the curved portion 30 a, theair from the centrifugal fan 15 can be more smoothly guided to theregion E on the side of the engine compartment. Accordingly, turbulenceor the like of the air flow due to the installation of the air guideplate 30 can be suppressed.

Embodiment 11

In the eighth to tenth embodiments, the evaporator 21 is inclineddownward at its one end corresponding to the forward end of the air flowbelow the evaporator 21, so that the air flows obliquely from theevaporator 21 into the heater core 22. As a result, there occurvariations in air blow speed distribution in the width direction of theheater core 22 (in the width direction of the vehicle). That is, thereoccurs an air blow speed distribution such that an air blow speed of airpassing through the heater core 22 becomes higher toward the lower endof the inclined evaporator 21 (toward the right side in FIG. 35).

Furthermore, the variations in air blow speed cause variations in heatexchanging amount in the left and right portions of the heater core 22,thus resulting in variations in temperature of the blow air.Accordingly, a feeling of the conditioned air by the air conditionerbecomes non-uniform in the left side and the right side in the passengercompartment, because of these variations in air blow speed andtemperature of the air, thus causing a deterioration in feeling ofconditioned air.

In view of the above problem, in the fourth embodiment, as shown in FIG.35, a plurality of air distributing plates 31 is provided in an airpassage formed between the evaporator 21 and the heater core 22, so asto uniform the air blow speed distribution in the width direction of thevehicle.

More specifically, the air distributing plates 31 are arranged atintervals so as to be perpendicular to an air receiving surface of theheater core 22, and the intervals of the plural (three in thisembodiment) plates 31 are set equal to each other. The air distributingplates 31 are formed integrally with the resin case of the airconditioning unit 2, more specifically, with the intermediate case 29 b.Accordingly, the air distributing plates 31 can be formed simply at alow cost.

In the eleventh embodiment, the air passed through the evaporator 21 isforcibly guided by the air distributing plates 31 located justdownstream of the outlet of the evaporator 21, and then flows normallyto the air receiving surface of the heater core 22. Accordingly,variations in air blow speed distribution in the width direction of theheater core 22 can be greatly reduced to uniform the air blow speeddistribution in the heater core 22.

Embodiment 12

The twelfth embodiment is intended both to uniform an air blow speeddistribution of air flowing into the evaporator 21 in the longitudinaldirection of the vehicle by using the air guide plate 30 and to uniforman air blow speed distribution of air flowing into the evaporator 21 inthe width direction of the vehicle.

Since the air directed from the blower 14 of the fan unit 1 flowssubstantially horizontally below the evaporator 21 and then changes itsdirection to a substantially vertical direction so as to enter theevaporator 21, the air blow speed at the forward end of the air flowbelow the evaporator 21 (the right end in FIG. 36) becomes higher thanthat at the other area.

The air guide plate 30 is formed integrally with the resin case locatedbelow the evaporator 21, more specifically, with the lower case 29 a,and a stepped concave and convex surface 32 is further formed integrallywith the lower case 29 a, thereby making uniform the air blow speeddistributions in the evaporator 21 both in the longitudinal direction ofthe vehicle and in the width direction of the vehicle.

The stepped concave and convex surface 32 extends in a direction (thelongitudinal direction of the vehicle) perpendicular to the direction ofthe air flow from the blower 14 (the width direction in FIG. 36). Inthis embodiment shown in FIG. 36, the stepped concave and convex surface32 is formed as a two-stepped surface having upper surfaces and lowersurfaces. According to an experimental result by the inventors, it hasbecome apparent that the height of each step between the adjacent upperand lower surfaces is preferably set to about 15 to 20 mm to uniform theair blow speed distribution.

The evaporator 21 is not limited to the aforementioned laminated type,but any other types may be adopted. For example, the evaporator 21 maybe of a serpentine type in which a multihole flat tube is meanderinglybent and a corrugated fin is combined with the bent tube.

Embodiment 13

FIGS. 37 to 43 show a thirteenth embodiment of the present inventionapplied to an air conditioner for an automobile. Referring to FIG. 37,an engine compartment A and a passenger compartment B is partitioned bya partition C (generally referred as a “fire wall” and made from an ironplate). A fan unit 1 of an air conditioner is so located as to be offsetfrom the central portion of the dashboard P in the width direction ofthe vehicle (e.g., offset to the left wheel the vehicle has a rightsteering wheel).

As shown in FIGS. 38 and 39, the fan unit 1 has at its upper portion aninternal air/external air selector housing 11 for selectivelyintroducing air inside the passenger compartment and air outside thepassenger compartment. The internal air/external air selector housing 11is formed with an external air inlet 12 for introducing the external airand an internal air inlet 13 for introducing the internal air. Insidethe internal air/external air selector housing 11, there is provided aninternal/external air selector door (not shown) for opening or closingthe external air inlet 12 and the internal air inlet 13.

As shown in FIGS. 38 and 39, the fan unit 1 has at its upper portion aninternal air/external air selector housing 11 for selectivelyintroducing air internal the passenger compartment and air outside thepassenger compartment. The internal air/external air selector housing 11is formed with an external air inlet 12 for introducing the internal airand an internal air inlet 13 for introducing the external air. Insidethe internal air/external air selector housing 11, there is provided aninternal air/external air selector door (not shown) for opening andclosing the external air inlet 12 and the internal air inlet 13.

A blower 14 is provided below the internal air/external air selectorhousing 11. The blower 14 is composed of a centrifugal multi-blade fan(scirocco fan) 15, a fan motor 16, and a scroll casing 17.

A rotary shaft of the fan 15 is so arranged as to direct in asubstantially vertical direction. The air sucked by rotation of the fan15 from the internal air/external air selector housing 11 through abellmouth shaped air inlet 18 (see FIG. 41) formed at an upper portionof the scroll casing 17 is directed toward an outlet of the scrollcasing 17 in a substantially horizontal direction (from the left to theright in the passenger compartment B as understood from FIGS. 37 and38).

As shown in FIGS. 37 and 38, an air conditioner unit 2 incorporating anair conditioning heat exchanger which will be described later is locatedat the central portion of the dashboard P in the passenger compartment Bin the width direction of the vehicle. In the air conditioning unit 2,an evaporator (cooling heat exchanger) 21 of a refrigeration cycle islocated substantially horizontally. The air directed from the fan unit 1enters the evaporator 21 from its lower side, and flows upward.

As shown in FIGS. 38 and 39, a heater core (heating heat exchanger) 22is located substantially horizontally on the downstream side of theevaporator 21 with respect to the airflow direction (on the upper sidein the passenger compartment). The heat core 22 utilizes an enginecooling water (hot water) as a heat source. A blow mode selector 23 (seeFIG. 39) is located on the upper side of the heat core 22 in thepassenger compartment (on the downstream side of the heater core 22).

In this embodiment, there is provided a hot water flow control valve 24(see FIG. 40) for controlling a hot water flow to the heater core 22 astemperature control means for controlling temperature of conditionedair, so that the hot water flow to the heater core 22 is controlled bythe hot water flow control valve 24 to thereby adjust an amount of heatof air by the heater core 22 and control a temperature of air to besupplied into the passenger compartment.

The blow mode selector 23 is provided to select a blow mode of air to besupplied into the passenger compartment. The blow mode selector 23includes a center face air passage 25 communicated with a center face(upper) air outlet (not shown) for discharging air toward the head of apassenger in the passenger compartment, two side face air passages 26communicated with two side face air outlets (not shown) for dischargingair toward the head of the passenger from the right and left sidesthereof, two foot air passages 27 communicated with two foot (lower) airoutlets (not shown) for discharging air toward the feet of thepassenger, and a defroster air passage 28 communicated with a defrosterair outlet (not shown) for discharging air toward a windshield. As shownin FIG. 37, the defroster air passage 28 is located on the front side ofthe center face air passage 25 in the longitudinal direction of thevehicle. The blow mode selector 23 further includes door means (platedoor, rotary door having a cylindrical outer peripheral surface, or filmdoor) for selectively opening or closing these air passages 25, 26, 27,and 28.

The blow mode selector 23 may have a known structure, and the detaileddescription thereof will be omitted herein. However, in brief, the blowmode selector 23 has a cylindrical shape extending laterally as viewedin FIG. 39. A rotary door (not shown) is rotatably provided in the blowmode selector 23 and has a cylindrical outer peripheral surface in whichopenings are defined to allow for the air passages. By selecting arotational position of the rotary door, the air passages 25, 26, 27, and28 are selectively opened or closed to select a desired one of aplurality of blow modes including a face blow mode, a bi-level blowmode, a foot blow mode, a defroster blow mode, and a combined foot anddefroster blow mode.

The evaporator 21 is provided with a thermal type expansion valve 21 a(see FIG. 41) as pressure reducing means for reducing the pressure of arefrigerant from a high-pressure refrigerant piping of a refrigerationcycle to thereby expand the refrigerant. The evaporator 21 is slightlyinclined with respect to a horizontal plane, so as to improve thedrainage of condensed water generated by the cooling operation. That is,as shown in FIG. 39, the evaporator 21 is inclined downward at its oneend (right end as viewed in FIG. 39) corresponding to the forward end ofthe flow of air directed to the lower side of the evaporator 21 by theblower 14.

An inclination angle θ of the evaporator 21 is set to preferably 10 to30 degrees to reduce an amount of water retained in the evaporator 21itself.

As shown in FIG. 42, the evaporator 21 is of a known laminated type suchthat its core portion 21 d is formed by laminating a plurality of metalthin plates of aluminum or the like which is superior in heatconductivity and corrosion resistance in a vertical direction in FIG. 42to construct a plurality of tubes 21 b, and by interposing a corrugatedfin 21 c between each pair of adjacent tubes 21 b.

A tank portion 21 e is provided at one end of the core portion 21 d todistribute the refrigerant to the tubes 21 b and collect the refrigerantfrom the tubes 21 b. There is formed inside each tube 21 b a U-shapedrefrigerant passage (see an arrow 21 f in FIG. 42) turned at the otherend of the core portion 21 d.

The tank portion 21 e is provided with a refrigerant inlet 21 g forintroducing the refrigerant of two phases of gas and liquid reduced inpressure by the expansion valve 21 a and with a refrigerant outlet 21 hfor discharging the refrigerant of gas evaporated in the core portion 21a.

The tank portion 21 e is located at the upper end of the inclinedevaporator 21, and the tubes 21 b are so located as to extend in thesame direction as the blowing direction of air directed from the blower14 (the direction from the left to the right as viewed in FIGS. 39 and40). Accordingly, the condensed water generated in the evaporator 21 isforced by the air flow from the blower 14 to smoothly flow on thesurfaces of the tubes 21 b to the lower end of the inclined evaporator21 (the right end in FIGS. 39 and 40).

The condensed water generated in the evaporator 21 is discharged from acondensed water drain pipe 30 provided below the lower end of theinclined evaporator 21 on the upstream side of the evaporator 21. Thedrain pipe 30 is formed integrally with a lower case 29 a of resin (seeFIG. 41) at its lowermost portion.

As shown in FIGS. 40 and 43, the corrugated fin 21 c has a flat surface21 i and a louver 21 j for guiding the air flow from the blower 14obliquely with respect to the flat surface 21 i. The louver 21 j isformed integrally with the flat surface 21 i by cutting and bending asby roller forming. The louver 21 j serves to cut off a thermal boundarylayer in the flat surface 21 i, thereby improving a heat transfercoefficient. In this embodiment, the louver 21 j is inclined withrespect to the flat surface 21 i in adverse directions on the upstreamside and the downstream side of the flat surface 21 i. Accordingly, asshown in FIG. 40, the air flow in the evaporator 21 becomes V-shaped.

The direction of inclination of the louver 21 j to the flat surface 21 iis so set as to offset non-uniformity of air blow speed distribution ofair passed through the evaporator 21 in the width direction of thevehicle, as described later. More specifically, the direction ofinclination of at least a downstream portion of the louver 21 j is setso that the air flow at the downstream portion is directed toward thetank portion 21 e.

FIG. 41 shows a structure where the apparatus in this embodiment isassembled. The fan 15 of the blower 14 is integrally connected to arotating shaft 16 a of the motor 16, and next inserted into the scrollcasing 17 formed integrally with the resin lower case 29 a. In thiscondition, the motor 16 is fixedly mounted at its flange portion 16 b tothe scroll casing 17.

The evaporator 21 is placed on an mounting surface of the lower case 29a, and a resin intermediate case 29 b is put on the lower case 29 a soas to sandwich the evaporator 21. Thus, the evaporator 21 is fixedbetween the lower case 29 a and the intermediate case 29 b.

An upper cover portion 17 a of the scroll casing 17 is formed integrallywith the intermediate case 29 b. The upper cover portion 17 a has thebellmouth shaped air inlet 18. The internal air/external air selectorhousing 11 is located on the bellmouth shaped air inlet 18 andintegrally mounted thereto.

The heater core 22 and the hot water control valve 24 are placed on amounting surface of the intermediate case 29 b, and a resin upper case29 c of resin is put on the intermediate case 29 b so as to sandwich theheater core 22 and the hot water control valve 24. Thus, the heater core22 and the hot water control valve 24 are fixed between the intermediatecase 29 b and the upper case 29 c.

The upper case 29 c is provided with the blow mode selector 23, centerface air passage 25, side face air passages 26, foot air passages 27,and defroster air passage 28. Further, the rotary door (not shown) isincorporated in the upper case 29 c. The cases 29 a, 29 b, and 29 c andthe internal air/external air selector housing 11 are detachablyconnected by using metal clips having elasticity or screws.

An operation of the thirteenth embodiment having the above structurewill now be described.

Referring to FIGS. 39 and 40, the air flowing into the internalair/external air selector housing 11 is directed into the scroll casing17 by the fan 15, and flows substantially horizontally in the scrollcasing 17 to the lower side of the evaporator 21. Then, the air flowchanges its direction to a vertical direction to enter the evaporator21, and the air is dehumidified and cooled in the evaporator 21. Thenthe air flows upward to enter the heater core 22, in which the air isheated.

In this embodiment, the hot water control valve 24 for controlling theamount of hot water to be supplied to the heater core 22 is used asconditioned air temperature control means. That is, a so-called flowcontrol reheat system is adopted to obtain a desired blowing airtemperature by controlling the amount of hot water in the hot watercontrol valve 24. The conditioned air reheated to a desired temperaturein the heater core 22 is distributed to a predetermined air passageselected by the rotary door of the blow mode selector 23 in the uppercase 29 c, and is discharged from the predetermined air outlet into thepassenger compartment.

With the above configuration of the embodiment, the following effectscan be obtained.

(1) Since the evaporator 21 and the heater core 22 are locatedsubstantially horizontally and laminated vertically (one above theother), a vertical space for the heat exchanger can be greatly reduced.As a result, the vertical dimension of the air conditioning unit can bemade sufficiently smaller than that of the conventional center-layoutunit. Further, since it is unnecessary to provide blowing ducts on thefront and rear sides of the heat exchanger, the dimension in thelongitudinal direction of the vehicle can also be reduced. Thus, the airconditioning unit can be made greatly compact, and it can be easilyinstalled in the passenger compartment.

(2) Since most of the components of the air conditioning unit have suchshapes as to be assembled vertically as shown in FIG. 41, the airconditioning unit can be easily assembled by one-directional assemblingsuch that the components are vertically laminated, so that the number ofthe assembling steps can be reduced.

(3) Since the evaporator 21 is inclined downward at its one endcorresponding to the forward end of the flow of air directed from theblower 14, and the tubes 21 b of the evaporator 21 extend along the airflow (in the width direction in FIGS. 39 and 40), the condensed water inthe evaporator 21 can be forced by the air flow to smoothly flow on thesurfaces of the tubes 21 b and be collected at the end of the inclinedevaporator 21 (the right end in FIGS. 39 and 40).

Then, the condensed water is discharged from the drain pipe 30 locatedbelow the lower end of the inclined evaporator 21. Thus, the condensedwater can be smoothly discharged from the evaporator 21.

(4) Since the condensed water in the evaporator 21 is dropped to theupstream side thereof, the condensed water dropped is warmed by the hotair before cooled. Accordingly, the temperature of the outer surface ofthe lower case 29 a is not so reduced, so that droplet on the lower case29 a can be greatly reduced or eliminated. Accordingly, it isunnecessary to provide a heat insulator usually mounted inside a case.

(5) By setting the direction of inclination of the louver 21 j of thecorrugated fin 21 c in the evaporator 21, the air blow speeddistribution of air passed through the evaporator 21 can be uniformed.An operation of uniformity of the air blow speed distribution byutilizing the inclination of the louver 21 j, which is the main featureof the present invention, will be described.

FIGS. 44A and 44B show a comparison sample on which the inventors haveexperimented for the air blow speed distribution. The air from theblower 14 is directed substantially horizontally so as to reach thelower side of the evaporator 21, and then flows through the evaporator21 from the lower side to the upper side while its direction is changedfrom the substantially horizontal direction to the substantiallyvertical direction. In this way, as accompany with the air flow beingbent, a main stream of the air flow is directed toward one end of theevaporator 21 corresponding to the forward end of the air flow (theright side in FIG. 44A) by the inertia of the air flow. In addition,since the evaporator 21 is inclined downward at this one end, the flatsurface 21 i of the corrugated fin 21 is not vertical, but is inclinedtoward this one end of the evaporator 21. As a result, it becomes easyfor the air having passed through the evaporator 21 to be directedtoward the side of this one end of the evaporator 21 (the right side inFIG. 44A).

In the comparison sample shown in FIGS. 44A and 44B, the direction ofinclination of the louver 21 j of the corrugated fin 21 c is set so thatthe air is directed toward the right side in FIG. 44A. Accordingly, theair having passed through the evaporator 21 is directed along theinclination of the louver 21 j toward the side of the one end of theevaporator 21 (the right side in FIG. 44A) as shown by the arrows a inFIG. 44A.

As a result, the air blow speed of air having passed through theevaporator 21 becomes higher on the side of the one end of theevaporator 21 than on the side of the other end of the evaporator 21(the side of the tank portion 21 e) as shown by the arrows b in FIG.44B. Thus, variations in the air blow speed distribution becomes large.

To the contrary, according to the air conditioning unit 2 in thisembodiment, the direction of inclination of the louver 21 j of thecorrugated fin 21 c is set so that the air is directed toward the leftside in FIG. 45A (toward the side of the tank portion 21 e).Accordingly, the air having passed through the evaporator 21 is directedalong the inclination of the louver 21 j toward the side of the otherend of the evaporator 21 (the left side in FIG. 45A) as shown by thearrows c in FIG. 45A.

As a result, although this embodiment adopts such a layout that the airflow is changed in its direction from the substantially horizontaldirection to the substantially vertical direction before entering theevaporator 21 and that the evaporator 21 is inclined downward at its oneend corresponding to the forward end of the air flow, the air blow speedof air having passed through the evaporator 21 can be made substantiallyuniform in the width direction of the vehicle as shown by the arrows din FIG. 45B. Thus, variations in the air blow speed distribution can beremarkably reduced.

Embodiment 14

FIG. 46 shows a fourteenth embodiment of the present invention. In thisembodiment, the direction of inclination of the louver 21 j of thecorrugated fin 21 c is not reversed between on the upstream side of theflat surface 21 i and on the downstream side thereof, but the directionis set to the same direction toward the tank portion 21 e. The otherconfiguration is the same as that of the thirteen embodiment.

Embodiment 15

FIG. 47 shows a fifteenth embodiment of the present invention. In thisembodiment, each louver 21 j has adjacent portions inclined in adversedirections, so that the air passes through the corrugated fin 21 cmeanderingly. Also in this embodiment, the direction of inclination ofthe louver 21 j on the most downstream side is set so that the air isdirected toward the side of the tank portion 21 e. Accordingly, the airblow speed distribution of air having passed through the evaporator 21can be uniformed.

The evaporator 21 is not limited to the aforementioned laminated type,but any other types may be adopted. For example, the evaporator 21 maybe of a serpentine type in which a multihole flat tube is meanderinglybent and a corrugated fin is combined with the bent tube.

Having thus described some specific embodiments of the present inventionapplied to an air conditioner for an automobile, it is to be noted thatthe application of the present invention is not limited to an airconditioner for an automobile, but the present invention may be appliedto any heat exchanger for air conditioning having a layout such that anair passage is bent across the heat exchanger.

Although the present invention has been fully described in connectionwith the preferred embodiments thereof with reference to theaccompanying drawings, it is to be noted that various changes andmodifications are to be understood as being included within the scope ofthe present invention as defined in the appended claims.

1. An air conditioner for a vehicle, comprising: a blower for blowingair; a case for defining an air passage through which air blown by theblower flows; and a cooling heat exchanger located in the caseapproximately horizontally such that the air blown by the blower flowsthrough the cooling heat exchanger, wherein the cooling heat exchangeris tilted from a horizontal surface to have a tilted lower end portionand a tilted upper end portion, wherein: the cooling heat exchangerincludes a plurality of tubes disposed in parallel with each other, anda plurality of corrugated fins each of which is disposed betweenadjacent tubes; the corrugated fin has a fin flat surface and isprovided with louvers for guiding air toward an inclination directionwith respect to the fin flat surface; and the louvers are proved suchthat a flow direction of air in an air outlet-side portion of thecooling heat exchanger is directed toward the tilted upper end portionof the cooling heat exchanger.
 2. The air conditioner according to claim1, wherein the louver is inclined downstream in an air flow from the finflat surface toward the tilted upper end portion of the cooling heatexchanger.
 3. The air conditioner according to claim 1, wherein thelouver has an inclined portion in the air outlet-side portion of thecooling heat exchanger, and the inclined portion is inclined downstreamin an air flow from the flat surface toward the tilted upper portion ofthe cooling heat exchanger.
 4. The air conditioner according to claim 1,wherein: the cooling heat exchanger further includes a tank portionconnected to one end of each tube; and the tank portion is positioned atthe tilted upper portion in the cooling heat exchanger.